Benchmark: array.some vs regex.test - new

Script Preparation code:

var appState = "active";
var regex = /inactive|background/;
var array = ['inactive', 'background'];

Tests:

array.some
array.some(v => v === appState)
regex.test
regex.test(appState);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array.some
regex.test

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
array.some	85540080.0 Ops/sec
regex.test	52745056.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):

LLMs can make mistakes. Check important info.

The benchmark provided compares two JavaScript approaches for checking if a specific value exists within an array or matches a regular expression. The focus is on performance, specifically execution speed, measured in executions per second.

### Approaches Being Compared

1. **`array.some(v => v === appState)`**
   - **Description**: This approach utilizes the `Array.prototype.some()` method, which tests whether at least one element in the array passes the condition implemented by the provided function. In this case, it checks if any element in the `array` matches the value of `appState`.
   - **Pros**:
     - **Readability**: The code is straightforward and easy to understand.
     - **Flexibility**: You can easily modify the condition being tested if needed.
     - **Short-circuiting**: The method stops testing as soon as it finds a match, which can improve performance in certain cases.
   - **Cons**:
     - **Array Iteration**: It may be slightly slower than direct comparisons for very small arrays, as it involves a function call and iterates through the array.

2. **`regex.test(appState)`**
   - **Description**: This approach uses a regular expression with the `RegExp.prototype.test()` method to check if `appState` matches the defined pattern (in this case, whether it is 'inactive' or 'background').
   - **Pros**:
     - **Conciseness**: It can be more compact, especially for more complex matching patterns.
     - **Versatility**: Regular expressions are powerful for pattern matching, which can be useful for more intricate validation scenarios.
   - **Cons**:
     - **Performance Overhead**: Regular expressions can introduce additional overhead, particularly for more complex patterns, because they can involve backtracking and more intricate processing.
     - **Complexity**: Regular expressions can be harder to read and maintain, especially for developers unfamiliar with regex syntax.

### Benchmark Results

The benchmark results demonstrate performance differences:

- **`array.some`**: Achieved approximately **85,540,080 executions per second**.
- **`regex.test`**: Achieved approximately **52,745,056 executions per second**.

From these results, it's clear that `array.some` is significantly faster in this particular test environment. This suggests that for simple equality checks against a small, static set of values, employing array methods may be more efficient than regular expressions.

### Other Considerations

- **Size of Data**: The performance can vary depending on the size of the array being tested or the complexity of the regex. For larger datasets, `array.some` may still hold its performance advantage. Complex regex patterns could also yield much slower performance compared to simple value checks.
- **Browser and Environment**: Performance metrics can depend significantly on the JavaScript engine of the browser. The benchmark is run in Chrome, and results may vary in other browsers due to differences in their JavaScript engines (e.g., V8 for Chrome, SpiderMonkey for Firefox).
- **Specific Use Cases**: If your use case involves simple value checks against a small array, `array.some` is likely the go-to choice. However, if you're performing more complex string matching against various patterns, regex may be necessary despite its potential for slower execution.

### Alternatives

1. **Array Includes**: For simple existence checks, `array.includes(appState)` can be used, which returns a boolean indicating whether a value exists in the array. It's straightforward and often more optimized than custom comparisons.
2. **Set Data Structure**: For frequent existence checks, using a `Set` data structure can provide average constant time complexity, as lookups in a set are generally faster compared to array iterations.
3. **For Loop**: A classic `for` loop can also be used for greater control over iteration and can be optimized further if needed.

In summary, while `array.some` performed better than `regex.test` in this benchmark, the choice between them should be guided by context, readability, and the specific matching needs of the application.

Related benchmarks:

array.some vs regex.test - new (version: 1)

Comparing performance of: array.some vs regex.test

Created: one month ago by: Guest

Jump to the latest result

array.some

regex.test

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one month ago):